Water skiing



Dec. 10, 1963 J. E. OMER 3,113,550 WATER SKIING Filed Oct.- 4. 1961 2Sheets-Sheet 1 A if J. E. OMER WATER SKIING Dec. 10, 1963 Filed Oct. 4,1961 2 Sheets-Sheet 2 United States Patent 3,113,550 WATER SKEEJG JohnE. Omar, York Harbor, Maine (1595 Holton Place, Charieston, S.C.) FiledOct. 4, 1961, Ser. No. 142,846 16 Claims. (Cl. 115-40) My inventionrelates to water skiing, and more particularly to a practical waterskiing propulsion apparatus.

Virtually all sustained water skiing is performed behind a tow boat andrequires as a minimum a suitable boat, a high powered engine and acareful boat operator. Everyone realizes that the sport would be greatlysimplified, and would grow in popularity if these tow auxiliaries couldbe dispensed with, at least after the skier is up on his skis, but therehas been no practical means of doing this.

I am aware of suggestions in the prior art for self-propelled devices,but these cannot satisfy the need. Marin, Patent No. 2,509,630, as anexample, suggests skiing with rockets which produce a vapor jet. This isimpractical since it requires unduly large amounts of fuel and istherefore incapable of producing a sustained ride. Moreover, rockets areexpensive, and their hand guiding as taught by Marin would make itdifficult for the operator to ski in the conventional sense of movinghis legs and body to guide him.

I have invented a practical means for self-propelled skiing which iseconomical and which can give a sustained ride to a water skier, thussolving the problem. I have actually used apparatus embodying theinvention myself,

being skied upon by a Water pump, and to pump it rearwardly withsufficient force to overcome the drag upon the skier caused by the waterintake as well as the normal resistance offered by the water surface andair, enabling him to ski successfully.

My invention, therefore, has as one principal objective, the utilizationof this concept to provide a practical water ski propulsion apparatus.

Another principal objective is to provide such apparatus whichincorporates a provision for buoyancy which both protects its drive unitand keeps the skier afloat when stopped.

Another objective of the invention is to provide air intake and exhaustpassages for the drive unit disposed in such a relationship with theremainder of the unit as to permit their exposure to the atmosphere whenthe skier is stopped in water over his head, providing for running theunit in that position.

Another objective of the invention is to provide for the drive unitsimple auxiliary apparatus for engine cooling and for protection againstwater from entering the exhaust or air-intake piping.

Another objective of the invention is to provide a drive unit in acompact, lightweight and inexpensive package suitable to bemass-produced.

Another objective of the invention is to provide for use with such apropulsion apparatus a highly efiicient water-intake arran ement whichminimizes drag.

Another objective is to provide for use with such apparatus protectionfor the skier from being injured by his skis.

Yet another objective is to provide a water ski with integralwater-intake means for use with such apparatus. This can providestability while skiing and permit walking.

In the drawings:

FIG. 1 is a perspective view of a skier stopped in water over his head,showing a preferred embodiment of the propulsion apparatus in position;

FIG. 2 is a perspective view similar to FIG. 1 with a skier in a generalattitude for successfully skiing.

FIG. 3 is a partially vertical cross-sectional and partially elevationalview of the drive unit of the apparatus of the preceding figures lookingtowards the back of the skier;

FIG. 4 is a vertical cross-sectional view of the drive unit taken online 4-4 of FIG. 3.

FIG. 5 is a horizontal cross-sectional view taken on line 5-5 of FIG. 3;

FIG. 6 is a top view of the unit of FIG. 3;

FIG. 7 is a side view of a portion of a ski and the water intake of theapparatus;

FIG. 8 is a view looking upwardly towards the bottom of an individualski;

FIG. 9 is a vertical cross-sectional view taken on line 9-9 of FIG. 8 onan enlarged scale;

FIG. 10 is a vertical cross-sectional View taken on line 19-10 of FIG.7;

FIG. 11 is a vertical cross-sectional view taken on line llll of FIG. 7;and

FIG. 12 is a perspective view of a control for the drive unit.

Referring to FIGS. 1 and 2, a water skier is shown with the apparatus.It comprises a drive unit 20 including a prime mover and a water pumphaving a water inlet. Water supply conduit here comprising flexible,noncollapsible tube 28 is connected to the unit and to a water-intakedevice 32 supported by a ski 30. The .unit has a rearwardly directedWater pump discharge port 34, here positioned directly adjacent thepressure side of the pump. Straps 36 are secured to the unit 20 anddisposed firmly about the shoulders of the skier.

As Will be seen from FIGS. 36, in this preferred embodiment the primemover is a two-cylinder reciprocating internal combustion engine 38comprised of aluminum, having a hand-held control pendant 26, provisionfor air and exhaust and a drive shaft 40. The water pump comprises acentrifugal pump impeller 42 driven by shaft 46 and mounted in a pumpcasing 44, which communicates at the inlet 45 with water supply tube 28,and which communicates with the pump discharge port 34 at the pressureside. A flow divider 46 is employed to separate water being pumpedthrough the port into two balanced streams. The pump impeller isbalanced with respect to the engine and freely rotatable with saidshaft, acting partially as the engine fly-wheel, thus saving in theweight of the unit.

A fuel tank 52 is mounted in the unit above the engine, and the startermeans is adapted for actuation in a floating environment. Oneadvantageous means is a wind-up starter spring, actuated by release ofan escapernent. For simplicity of illustration the starter in thefigures is shown as a cord 54 connected in a conventional way to theengine and extending out of the unit through a rubber bellows seal 55.

A small segment of the flow of water from the pressure side of the pumpis directed through a cooling water inlet tubing 48 to the engine,around the cylinders thereof and is expelled through downwardly directedoutlet 50.

A sealed drive unit housing 21 surrounds the engine, the pump and thetank, and defines a substantial volume preferably occupying about twicethe space measured in cubic feet as the numerical value of the weight ofthe engine in pounds divided by 60, the latter being the approximateweight of water in pounds per cubic foot. In other words, the casing andcontents displaces a greater weight of water than its own weight. In theexcess space flotation material '56 such as lightweight expandedpolystyrene foam is packed. Preferably, the forward side of the housinghas a vertically curved surface 58 as shown in FIG. 4, shaped to conformto the shoulders and back of the skier to feel comfortable when thewater outlet port 34 is positioned in horizontal alignment with hiscenter of gravity. It is supported there by the straps 36 adapted forthe purpose. While the port must be disposed to direct at least a majorportion of the water rearwardly of the skier, a small downward componentsuch as that through outlet 50 can serve to support the unit, taking itsweight off the skier. Equally, the skier can lean backwards, thusdirecting the port slightly downwards, or the port can be directedslightly downwards relative to the housing, enabling the skier to standupright while obtaining the same effect. A lateral component will applya turning moment on the skier.

Air and. exhaust pipe apertures 22 and 24 are located above the driveunit housing as indicated in FIGS. 3 and 4-. Air and exhaust isolationvalves are provided at these for the purpose of preventing entry ofwater. An isolation valve actuator in the form of a flotation and impactactuatable element 60 pivots to release spring valves 61 which move invalve giudes 63 to tightly close the apertures in the event of a fall bythe skier. To start and operate the motor, the valves are cocked open asshown in FIG. 4.

The drive unit as thus defined not only has sufficient buoyancy tosupport itself, but it aids in supporting the skier when he is stoppedin the water, and together with the skis can position a crouched skieras in FIG. 1 with the trunk of his body generally vertical and the pipeapertures 22. and 24 exposed to the atmosphere. In this position theskier can pull the cord 54- and start the engine, and thereafter he canbe brought to skiing position either by the apparatus alone or with thetemporary aid of atowv.

The drive unit can displace approximately /2 to 1 cubic foot of waterand weigh 15 to 30 pounds, depending upon the power and buoyancyrequirements. In my experimental apparatus the unit including thehousing weighed 24 pounds and displaced 30 pounds of fresh water, .48cubic foot.

The engine -I employed in my experimental apparatus was a one cylinder,2 cycle aluminum engine weighing 13% pounds and rated at 7 horsepower at4500 r.p.m., manufactured by Tecumseh Products Company, Model AH82.Numerous other types of engines are suitable.

The water pump may be of any construction, e.g., turbine, centrifugal orgear type, which will discharge the required amount of water at asufficient velocity to produce thrust to maintain forward motion. In myexperimental apparatus, I employed a centrifu gm pump, with singlesuction overhung impeller which is satisfactory for this purpose. Theimpeller had a 3.656 inch diameter. It operated at speeds between 3000and 4000 r.p.m., the same as the engine speeds, there being no need fora reduotion gear system between the engine and impeller, 21 veryimportant advantage. During skiing the drive unit pumped as much as 46c.f.rn. through the discharge port which had a cross-sectional area of2.18 inch thus providing more than an adequate velocity head.

Referring to FIGS. 7-l-1, the preferred water-intake device 32 compriseson the bottom of at least one ski 30 at least one fin having at leastone opening to admit water to its interior, but preferably, as shown, apair of intake fins 62 disposed apart in catamaran fashion. Elongatedintake slots 64 are disposed near the lower edges of these fins andcommunicate with the body of Water being skied upon. Preferably, at thefront of each fin is an intake scoop 66. A pivoted valve member 63having a smooth curved outer face is disposed to close the scoop openingand provide a streamlined aspect, and a weighted flap-type lever 70which tends by its Weight to keep the opening open and the flap surfaceextending downwardly is connected to the valve and disposed in the waterpath between the fins for regulating the water flow as will be discussedherein. With suction applied to such intake openings, the ski acts as acavitation plate, preventing entry into the intake of air bubbles whichform as a result of high fiuid velocities and reduced pressure. This inturn prevents pump cavitation.

The interior of each fin communicates with a T manifold 72 at the lowerend of the water supply tube 28, secured to riser 73 on the ski at thejoint 74 shown in FIG. 11. Preferably, a foot valve 75- is disposed ineach leg of the T which prevents loss of prime in the event one or bothskis is temporarily raised out of the water as during a jump or othermaneuver. However, even without this valve, loss of prime would only betemporary, since the forward velocity of the skier would immediatelyforce water to the pump when re-entering the water.

Referring particularly to FIGS. 7 and 9, a safety hold ing device ispreferably provided to permit separation of the skier from his ski inthe event of a fall. This preferably includes a catch 76 engaged with asuitable tube abutment, the latter being directed away from the end ofthe tube 28. A pivoted heel plate 77 is linked to the catch so that theplate when pressed down causes the catch 76 to move towards the tube andengage the abutmerit thus restraining the end portion of the tube fromleaving the riser. A spring 78 is adapted to urge the catch outwardlyfrom the tube, which automatically releases the catch when the heelpressure on plate 77 is released to permit removal of the tube from theriser. In norm-a1 operation the foot is inserted in the slipper binding80, and the heel normally bears upon the plate 77. The bottom of eachfin has a substantial horizontal extent in the direction of the ski axisadapted to permit walking with the skis. At spaced-apart pointsantifriction means are preferably installed, here partially exposed,rotatable spherical balls 90 to permit sliding movement relative to hardsurfaces.

Referring to FIG. 12, at the hand end of the power control pendant 26 isa hand-carried console 80 with suitable means for controlling thethrottle, the choke and the ignition switch S2, 84 and 86 respectively.

To commence operation, the skier may walk into the water on thespaced-apart fins. When he gets into sulficiently deep water, he lowershimself allowing the skis and the drive unit to buoy him. The isolationvalve control 60 is cocked in the open position, the control console isset and the engine is started. The pump draws water through the tubing28 from the fins and forces it out through the discharge port 34. Theskier uses his body motions to direct the stream of water enabling himto maneuver in the water. As soon as smooth operation of the engine isobtained, and he is in the position of FIG. 1, the skier opens up theengine full throttle. From here he may be assisted to skiing position bythe temporary use of a tow boat, or he can rely on his engine alone.

The effect of the discharged water from the power unit is to force theskier forward, overcoming the restraining forces and his inertia. Withthe skis disposed with tips sloped upwardly as shown in FIG. 1, thethrust and the skis tend to bring him to the surface.

As soon as the skier commences skiing, he is able to use his legs andbody to guide his skis and the pump outlet in a technique more similarto snow skiing than that employed in conventional water skiing. With theelimination of the tow rope and the constant pull from an extendeddistance and with the lateral stability afforded by the fins, he is freeto make much sharper turns. The bottoms of the fins of the skis equippedas shown or with skids or antifriction material such as fluorocarbonplastics enable him to negotiate jumps.

In the water intake device during operation, the scoop openings 66create a velocity head which fills the fin and tube under pressuregreater than atmospheric. Thus the operation does not depend entirely onvacuum drawing up of the water, and the skier can negotiate a jump outof the water without permanently losing power. With increase in speedthe weight of the scoop valve control 70 is partially overcome by theforce of the water. It pivots rearwardly tending to align with the flowof water between the fins, and this closes the water scoop 66 at leastpartially, thereby serving as a speed responsive control automaticallyregulating the supply of the water, which otherwise could increase toorapidly and increase drag as speed increases. With the valve in closingposition, the leading edge of the fin is streamlined. When the scoop isnot employed, all water enters through slots 64.

The water inlet fins give lateral stability similar to that of a centerboard in a boat, and through a possible catamaran effect they may reducedrag.

At the end of a run, or whenever the skier loses his balance and falls,the valves at the air and exhaust pipe apertures automatically close,stopping the engine, and with release of heel pressure, the catch 76disengages the tubes 28. These slip free from risers 73 thus separatingthe skier from his skis, which avoids dragging the ski which mightstrike the skier.

It will be seen that -I have provided apparatus which is lightweight andsimple to manufacture, which eliminates the need for a tow boat duringskiing and is safe for water skiing when alone. Such factors as bodyguiding, increase in maneuverability and dispensing with constant pullon the arms make water skiing with my device more enjoyable andthrilling than conventional skiing.

Numerous modifications can be made in certain specific details of theinvention within its spirit and scope.

What is claimed is: 1. A water ski propulsion apparatus comprising awater-intake means adapted to be supported by at least one ski, alightweight prime mover, a water pump actuated by said prime mover,means for mounting said prime mover and pump on the back of a skier,said pump having a water inlet, a flexible, noncollapsible conduit forconducting Water =fiom said intake means to said inlet,

and a water discharge port in communication with the pressure side ofsaid pump adapted to direct water rearwardly of said skier.

2. The apparatus of claim 1 wherein said prime mover is an internalcombustion engine.

3. The apparatus of claim 2 wherein said prime mover and pump areenclosed in a housing capable of displacing a volume of water weighingin excess of the weight of the housing and its contents, the volume ofsaid housing not occupied by said prime mover and pump beinghermetically sealed, adapted to provide buoyancy.

4. The apparatus of claim 1 wherein said water-intake means comprises atleast one fin mounted on the bottom of a ski and extending downwardlytherefrom, said fin having at least one opening for receiving water fromthe body of water being skied upon, and having passage means connectingthe interior of said flexible, noncollapsible fin to said conduit.

5. The apparatus of claim 4 wherein said water-intake means comprises apair of downwardly extending fins mounted on the bottom of said ski,said fins being spaced apart to permit water to pass therebetween, andhaving openings through which water may enter to proceed through saidpassage to said flexible, noncollapsible conduit.

6. The apparatus of claim 5 wherein said fins are shaped to provide astable support for walking on land.

7. The apparatus of claim 4 wherein said conduit is a flexible tubeseparable from said water intake means and is connected thereto by areleasable device comprising a holding means adapted to hold said tubeagainst upward movement relative to said ski, a lever heel plate mountedon said ski adapted when pushed against said ski by the heel of a skierto force said holding means to engage said tube, said holding meansbeing adapted to release said tube on release of pressure by said heelto permit removal of said tube with respect to said intake means in theevent of a fall.

8. The apparatus of claim 4 wherein said opening is in the front of theski defining a water scoop adapted to provide a velocity head at saidopening and within said conduit during skiing.

9. The apparatus of claim4 wherein said aperture is at least oneelongated slot in the side of said fin near its lower edge.

10. The apparatus of claim 3 including air-inlet and exhaust passagesextending upwardly from said engine to apertures, strap means mounted onsaid housing adapted to be secured to said skier and buoy him whilesimultaneously holding said air and exhaust apertures above the watersurface.

=11. The apparatus of claim 10 wherein isolation valve means is providedfor said air-inlet and exhaust apertures, and actuator means is providedin combination with said valve means, adapted to respond to floatingeffect of water and to impact, to close said valve to pre vent entry ofwater into said engine.

12. A drive unit for a water ski propulsion apparatus comprising ahousing having a forward surface shaped to rest upon the back of askier, a lightweight, reciprocating, internal combustion engine in saidhousing, a water pump in said housing comprising an enclosing casing andan impeller adapted to be actuated by said engine, means for connectinginlet water tubing to said pump, a

water discharge port for directing water from said pump rearwardly fordriving said skier forward, a fuel tank mounted adjacent said engine onsaid housing, flotation material in said housing around said engine, andair-inlet and exhaust piping extending upwardly from said engine abovesaid housing.

13. The drive unit of clairn 12 wherein said discharge port is providedin the rear surface of said housing, and said housing has shoulderstraps mounted and adapted to support said housing relative to saidskier positioning said port substantially in horizontal alignment withthe center of gravity of said skier.

14. The apparatus of claim 2 wherein flotation material surrounds theinternal combustion engine in a quantity sufiicient to float said engineand said pump.

15. A ski adapted for use with a prime mover-water pump combination,said ski having a foot binding, at least one downwardly extending hollowmember, at least one opening in said hollow member for communicatingwith the body of water being skied upon, a passage defined upwardly fromsaid hollow member through the ski to an outlet located intermediate theends of the ski, adjacent said foot binding, said outlet positioned tofurnish water for a pump on the back of a skier and means for connectinga flexible tube in communication with said outlet, said opening beingdisposed in the forward end of said hollow member as a water scoop and avalve disposed within said hollow member, adapted to at least partiallyclose said opening and present an outwardly disposed strearnlinedsurface to decrease drag on said ski as it moves through the water, avalve actuator extending outside said hollow member into the body ofwater, adapted to be actuated by the movement of water relative to saidski to at least partially close said valve.

16. A ski adapted for use with a prime mover-water pump combination,said ski having a foot binding, at least one downwardly extending hollowmember, at least one opening in said hollow member for communicatingwith the body of water being skied upon, a passage defined upwardly fromsaid hollow member through the ski to an outlet located intermediate theends of the ski, adjacent said foot binding, said outlet positioned tofurnish water for a pump on the back of a skier and means for connectinga flexible tube in communication with said outlet, said flexible tubebeing separable from said ski, and said means for connecting saidflexible tube in communication with said outlet comprising a releasableholding means adapted to hold said tube in connection with said outletby pressure of a foot in position on said ski, and adapted to releasesaid tube on loosening movement of said foot relative to said ski.

1,607,244 Diller Nov. 16, 1926 Marin May Steele Apr.

Fifer June McKinney July Tierney Feb. Kincaid Mar.

FOREIGN PATENTS Germany Oct.

1. A WATER SKI PROPULSION APPARATUS COMPRISING A WATER-INTAKE MEANSADAPTED TO BE SUPPORTED BY AT LEAST ONE SKI, A LIGHTWEIGHT PRIME MOVER,A WATER PUMP ACTUATED BY SAID PRIME MOVER, MEANS FOR MOUNTING SAID PRIMEMOVER AND PUMP ON THE BACK OF A SKIER, SAID PUMP HAVING A WATER INLET, AFLEXIBLE, NONCOLLAPSIBLE CONDUIT FOR CONDUCTING WATER FROM SAID INTAKEMEANS TO SAID INLET, AND A WATER DISCHARGE PORT IN COMMUNICATION WITHTHE PRESSURE SIDE OF SAID PUMP ADAPTED TO DIRECT WATER REARWARDLY OFSAID SKIER.